The Holsteen

One of the sandstone blocks, in the northernmost part of the Holsteen site, would have been used as a so-called 'polissoir' or polishing stone by Neolithic man. The numerous cavities in the rock, which gave De Holsteen its name, would have been caused by biological activity, both of animals and plants, and were created prior to petrification. More information and literature: inventaris.onroerenderfgoed.be/erfgoedobjecten/84272

The Holsteen is the collective name for eight large, Miocene sandstones.
The sandstones have irregular holes and the most northern stone also has grooves and a polishing surface.
This last stone is the only permanent prehistoric polishing stone in Flanders.
The site has been protected as a landscape heritage site since 1967.

Source: Wikipedia

Holsteenweg without number (Zonhoven)
The Holsteen, an ensemble of ten enormous sandstone blocks in the eastern part of the municipality of Zonhoven, is mentioned for the first time in 1862 in the scientific literature.